P1507

DTC P1507






GENERAL DESCRIPTION
The ISCA (Idle Speed Control Actuator) is designed to maintain a steady desired idle speed. Idle airflow is adjusted through the idle air actuator in order to maintain the desired idle speed under various load conditions. Load conditions vary due to numerous factors, such as engine temperature, air conditioning, electrical load and power steering load.

DTC DESCRIPTION
If there is Open or Short to ground in ISCA(closing coil) circuit, ECM/PCM sets DTC P1507.

DTC Detecting Condition:

Specification:

Schematic Diagram - A/T:

Schematic Diagram - M/T:

Signal Waveform And Data:

MONITOR SCANTOOL DATA
1. Connect scantool to Data Link Connector(DLC).
2. Warm up the engine to normal operating temperature.




3. Monitor the "ISCA" parameters on the scantool.
4. Are the parameters displayed correctly?

YES - Fault is intermittent caused by poor contact in the sensor's and/or ECM's connector or was repaired and ECM/PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of vehicle Repair" procedure.

NO - Go to "Terminal and connector inspection" procedure.

TERMINAL AND CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?

YES - Repair as necessary and go to "Verification of vehicle Repair" procedure.

NO - Go to "Power circuit inspection" procedure.

POWER CIRCUIT INSPECTION
1. Key "OFF".
2. Disconnect ISCA connector.
3. Key "ON".




4. Measure the voltage between terminal 2 of ISCA harness connector and chassis ground.

Specification : B+

5. Is the measured voltage within specification?

YES - Go to "Control circuit inspection" procedure.

NO - Repair Open or Short in power circuit and then, go to "Verification of Vehicle Repair" procedure.

CONTROL CIRCUIT INSPECTION
1. Check Open in control circuit.
a. Key "OFF".
b. Disconnect ISCA connector and ECM/PCM connector.







c. Measure the resistance between terminal 3 of ISCA harness connector and terminal 22/C01-2 of ECM/PCM harness connector. [A/T]Measure the resistance between terminal 3 of ISCA harness connector and terminal 25/C01 of ECM/PCM harness connector. [M/T]

Specification : Below approx. 1 ohm

d. Is the measured resistance within specification?

YES - Go to "Check Short in Control circuit" procedure.

NO - Repair Open in control circuit and then, go to "Verification of Vehicle Repair" procedure.

2. Check Short in control circuit.
a. Key "OFF".
b. Disconnect ISCA connector and ECM/PCM connector.




c. Measure the resistance between terminal 3 of ISCA harness connector and chassis ground.

Specification : Infinite

d. Is the measured resistance within specification?

YES - Go to "Component inspection" procedure.

NO - Repair Short to ground in control circuit and then, go to "Verification of Vehicle Repair" procedure.

COMPONENT INSPECTION
1. ISCA visual check.
a. Key "OFF".
b. Disassemble ISCA.
c. Check contamination, damage or stuck on ISCA.
d. Check the operating sound when key turns "OFF" to "ON".
e. Is ISCA O.K?

YES - Go to "ISCA check" procedure.

NO
- Substitute with a known - good ISCA and check for proper operation.
- If the problem is corrected, replace ISCA and go to "Verification of Vehicle Repair" procedure.

2. ISCA check.
a. Key "OFF".
b. Disassemble ISCA.
c. Measure the resistance between terminal 1 and 2 of ISCA harness connector. (Component side)

Specification:

d. Measure the resistance between terminal 2 and 3 of ISCA harness connector. (Component side)

e. Is the measured resistance within specifications?

YES
- Substitute with a known - good ECM/PCM and check for proper operation.
- If the problem is corrected, replace ECM/PCM and go to "Verification of Vehicle Repair" procedure.

NO
- Substitute with a known - good ISCA and check for proper operation.
- If the problem is corrected, replace ISCA and go to "Verification of Vehicle Repair" procedure.

VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
2. Clear the DTCs and Operate the vehicle within DTC Enable conditions in General information.
3. Are any DTCs present ?

YES - Go to the applicable troubleshooting procedure.

NO - System is performing to specification at this time.